New Aspects of Actinides (Th, U and Np) Chemistry in Oxo-Selenium System

摘要

Complexity of actinide (An) chemistry in aqueous oxosaltsystems is dominated by their redox behavior. In systemswhere oxo-salts are also redox sensitive, as for examplein selenium and iodine based systems, the matter becomeseven more complex. In order to better understand thechemistry of An in Se based oxo-systems we performed aseries of systematic study on reactivity and phase formationof An bearing selenates and selenites in Th, U and Np systems.Thorium is a good modeling element for An~（Ⅳ) becauseit is not redox sensitive and crystal chemically is very similarto U~（Ⅳ), Np~（Ⅳ), and Pu~（Ⅳ). Uranium is quite stable in its UVIform under ambient atmospheric conditions and can mimichigher AnVI from a crystal chemical point of view. Neptuniumshows a great diversity in oxidation states and its chemistryperfectly illustrates the complexity of An based systemsin general.